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Re: Re: Re: New tests to cover missing algebraic forms

From: Eric Prud'hommeaux <eric@w3.org>
Date: Tue, 14 Aug 2007 10:55:23 -0400
To: Chimezie Ogbuji <ogbujic@ccf.org>
Cc: W3C Data Access Working Group <public-rdf-dawg@w3.org>
Message-ID: <20070814145523.GC5513@w3.org>
* Chimezie Ogbuji <ogbujic@ccf.org> [2007-08-14 10:17-0400]
> 
> > >
> > > Thanks, Chimezie.
> > >
> > > I added a trailing period to algebra/join-combo-graph-2.ttl and to 
> > > optional/complex-data-1.ttl and to optional/result-complex*.ttl to get the 
> > > parser I'm using to be happy. I also removed a stray " from a namespace 
> > > declaration in result-opt-complex-2.ttl .
> 
> Well spotted, thanks.
> 
> > >> The new tests are:
> > >> http://www.w3.org/2001/sw/DataAccess/tests/data-r2/algebra/manifest#join-combo-1
> > >> Algebra form: Join(LeftJoin(BGP(..),{..}),Join(BGP(..),Union(..,..)))
> > >> Comment: Tests nested combination of Join with a BGP / OPT and a BGP /
> > >> UNION
> > >> PREFIX :    <http://example/>
> > >> SELECT ?a ?y ?d ?z
> > >> {     ?a :p ?c OPTIONAL { ?a :r ?d }.     ?a ?p 1 { ?p a ?y } UNION { ?a 
> > >> ?z ?p } }
> > >
> > > The result set here has two bindings for ?y. I'm guessing that one (the one 
> > > bound to a literal) should be ?d 
> 
> Yes, it is supposed to be ?d.  I.e.,:
> 
> ?a -> http://example/x1
> ?y -> http://www.w3.org/1999/02/22-rdf-syntax-ns#Property
> ?d -> 4^^xsd:integer
> 
> I've made this change
> 
> > but even then I don't think I'd agree with 
> > > the test. Does the test assume RDF entailment (specifically knowing that if 
> > > :a :b :c then :b a rdf:Property)?
> 
> As written it doesn't, since the relevant statement (about rdf:Property)
> is explicitly asserted in the dataset:
> 
> :p a rdf:Property
> 
> Though I can see how the use of rdf:Property would seem to suggest RDF
> entailment...

I noted a lack of sensitivity to the " UNION { ?a ?z ?p }" clause. I added
  :x1 :z :p .
to the data and got
┌───────────────────┬─────────────┬─────────────────┬──────────────────┐
│                  a│            y│                d│                 z│
├───────────────────┼─────────────┼─────────────────┼──────────────────┤
│<http://example/x1>│<...Property>│"4"^^<...integer>│                  │
│<http://example/x1>│             │"4"^^<...integer>│<http://example/z>│
└───────────────────┴─────────────┴─────────────────┴──────────────────┘

Should I check it in?
-- 
-eric

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Received on Tuesday, 14 August 2007 14:55:29 GMT

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